diff --git a/mvcc/kvstore.go b/mvcc/kvstore.go
index c2ef4b252..e367ebbb3 100644
--- a/mvcc/kvstore.go
+++ b/mvcc/kvstore.go
@@ -176,6 +176,7 @@ func (s *store) compactBarrier(ctx context.Context, ch chan struct{}) {
 }
 
 func (s *store) Hash() (hash uint32, revision int64, err error) {
+	// TODO: hash and revision could be inconsistent, one possible fix is to add s.revMu.RLock() at the beginning of function, which is costly
 	start := time.Now()
 
 	s.b.ForceCommit()